A known drive unit of the above mentioned type for electrically powered vehicles has a speed reducer with a differential mounted at one end of the electric motor, the axle to the driving wheel on the differential side being a short axle, while the axle to the other driving wheel extends from the differential, through the speed reducer and through the electric motor to the opposite side of the motor. Such drive units have up to now had a single gear ratio and the described design is compact and it has achieved the desired reduction of the electric motor rpm to the desired rpm for the drive wheels.
One of the many problems which must be solved before achieving a commercially viable electrically powered car is reducing the weight and volume of the drive unit and its energy source, i.e. the battery pack. Up to now, research and development has largely been focussed on the latter problem, i.e. finding means and methods for more effective storage of electrical energy than what is known today.